Your brakes are arguably your car’s number one safety feature. While hydraulic braking systems are almost perfect, they still have their issues. Usually these are common and easy to spot if you know what to look for. Keep reading for the low down on how hydraulic brakes work, what the most common problems are and how to know when there’s something wrong with your brakes.
How do hydraulic brakes work?
To diagnose problems and have the correct repairs made, it’s important to have a basic understanding of how hydraulic braking systems work. First, we’ll cover the main components of a hydraulic brake system.
Main parts of a hydraulic braking system
- Brake pedal: This is the pedal you apply pressure to with your foot
- Master cylinder: Converts the force from the brake pedal into hydraulic pressure
- Brake pipes: The pipes that connect the master cylinder with the brake callipers/wheel cylinders and facilitate the travel of the brake fluid
- Brake Callipers/Wheel cylinders: Hydraulic pressure moves pistons in the brake callipers/wheel cylinders, which then applies pressure to the brake pads/shoes
- Brake Disc/Drum: The brake disc/drum is connected to the wheels, providing a surface for the brake pads/shoes to clamp against to slow rotation.
How the system works
Brake fluid is unable to be compressed, which makes it ideal for transferring motion through hydraulic force. The steps below outline exactly how this system works:
- The driver applies pressure to the brake pedal
- When the brake is applied it pressurises the brake fluid in the master cylinder
- It then travels along the brake pipes to the wheel cylinder
- The pressurised brake fluid activates the brake pistons
- The brake pistons then pressurise the brake pads
- When the brake pads squeeze into place, that’s what causes your car to stop
Common problems with hydraulic braking systems
There are a few common issues when it comes to hydraulic brakes. If you know them, you’ll be in a position to diagnose them yourself, which will increase your safety and potentially even save you some cash.
- Worn brake pads: Due to friction, brake pads become worn over time. This creates more space and requires more brake fluid, which is taken from the master cylinder.
- Corrosion of main cylinder: As brake fluid is made with alcohol, it can corrode the main cylinder over time when it absorbs moisture and becomes contaminated. Corrosion can lead to damage, which means you’ll need to replace your master cylinder.
- Failure of internal seals: Internal seals hold pressure and stop the wheel cylinder from leaking.
- Air in wheel cylinder: If air enters a leaking wheel cylinder, you will need to bleed the brakes. This involves releasing the air from the brake system by applying pressure. If your brake pedal feels soft or spongy, it could indicate air has entered he system.
- Locked wheels: This can happen when the main cylinder is corroded due to contamination of brake fluid or after a replacement of the main cylinder. After replacing the cylinder, you should ensure the port remains open so it can build up a reservoir of brake fluid.
How to tell if there’s a problem with your brakes
While we don’t recommend trying to fix your own brakes if you don’t know what you’re doing, there are certainly some warning signs you can look out for. This way you’ll know exactly when you should be taking your car to get checked out. Get your car to an expert if you notice any of the following:
- Low brake fluid
- Squeaking or grinding noises
- Soft or spongy brake pedal
- Brake warning light lit up on dashboard
- Car pulling to one side when braking
- Car takes longer than usual to stop at traffic lights
- Shaking steering wheel while braking
- A scraping noise